1. Field of the Invention
The present invention relates to a head slider supporting device, a disk device and a suspension, and, in particular, to a magnetic head slider supporting device, a magnetic disk device and a suspension.
As a frequency of a signal which an information processing apparatus handles increases, a magnetic disk device is demanded to increase a signal writing frequency, from 70 MHz at the present time, to, for example, 200 through 300 MHz. In order to increase the signal writing frequency, it is necessary to reduce the inductance and the electrostatic capacity of a signal transmitting path from a magnetic head slider to a head IC. For this purpose, it is effective to provide the head IC near to the magnetic head slider. This is also effective to cope with a feeble recording signal obtained through reproduction by a magnetic head. On the other hand, the disk device is demanded to be thin. It is necessary that the head IC does not prevent the magnetic disk from being thin and that the head IC is loaded in a condition where the head IC does not come into contact with the magnetic disk or the like even when a shock is applied to the magnetic disk device.
2. Description of the Related Art
Magnetic disk devices, in each of which a head IC for amplifying a signal read through a head is installed on an actuator arm, are disclosed in Japanese Laid-Open Patent Application Nos.62-217476, 3-108120, 3-187295, 3-192513 and so forth.
However, in each of the above-mentioned magnetic disk devices, because the distance between the head and the head IC is long, it is difficult to reduce the inductance and the electrostatic capacity of the signal transmission path from the head to the head IC. Further, the head IC is packaged by a synthetic resin, and thereby, is thick. As a result, in some cases, in order to prevent the head IC from coming into contact with a magnetic disk or the like when a shock is applied to the magnetic disk device, it is necessary to elongate the distance between adjacent magnetic disks. As a result, the magnetic disk device is thick. Further, because the head IC is packaged by the synthetic resin, the head IC is heavy. As a result, the weight of the magnetic head slider supporting device increases. Thereby, the flying stability of the magnetic head slider above the magnetic disk is degraded, and, also, there is a possibility that, when the magnetic head slider comes into contact with a magnetic disk due to a strong shock applied to the magnetic disk device, the shock applied to the magnetic disk is so strong that the magnetic disk is damaged.
As shown in FIG. 1, in a head slider supporting device 1, on the top surface 2a of a suspension 2 (hereinafter, the position of the suspension shown in FIG. 1 is a reference position thereof, and `the top surface` of the suspension means the top surface in this position of the suspension), wiring patterns 3 are formed from the extending end to the fixed end of the suspension 2, and a magnetic head slider 4 is loaded on the top surface 2a of the suspension 2 at the extending end of the suspension 2.
Here, provision of a head IC 5 will be considered. Due to the arrangement of the wiring patterns 3, a surface at which the head IC is loaded is limited to the top surface 2a of the suspension 2. When considering an increase of the signal writing frequency, it is preferable that the head IC 5 be provided at a position near to the magnetic head slider 4. Therefore, it is assumed that the head IC 5 is loaded on the top surface 2a of the suspension 2 near the magnetic head slider 4.
In order to prevent the head IC 5 from coming into contact with a magnetic disk 6 even when a strong shock is applied to the magnetic disk device, it is necessary that a gap 7 of the distance `a` equal to or longer than 0.15 mm be provided between the head IC 5 and the magnetic disk 6.
Recently, in order to thin the magnetic disk device, the magnetic head slider 4 of a small size (a so-called pico-slider, the height `b` of which is 0.3 mm) has been used. As a result, the distance `c` between the suspension 2 and the magnetic disk 6 is small.
When considering a bare head IC 5, the bare head IC 5 is cut out from a wafer. Accordingly, the thickness of the bare head IC 5 is determined by the thickness of the wafer. At the present time, it is difficult to make the wafer thinner than 0.3 mm. Accordingly, the height (thickness) `d` of the head IC is approximately 0.3 mm minimum.
Therefore, when the bare head IC 5 is simply loaded on the top surface 2a of the suspension 2, it is difficult to obtain the gap equal to or longer than 0.15 mm between the head IC 5 and the magnetic disk 6.